This invention relates to an IC card with input keys for entering numerical data and a display section for displaying the content of a memory device, and more particularly to such an IC card with an improved input section having fewer keys.
Memory cards such as credit cards are used in various areas including bank and other financial operations. Memory cards of the most common type are formed by attaching a magnetic memory medium such as a magnetic tape onto a plastic card. More recently, IC cards are made with an active element such as an IC circuit buried inside such that not only can the owner's personal data be freely written therein or read therefrom but also stored data can be securely protected. As shown in FIG. 1, such an IC card 10 is typically comprised of a main body 11, a display section 12 on the main body 11 for displaying the content of a memory device (not shown), a key input section 13 for entering input data such as a password and a connecting terminal (not shown) for connecting the card 10 with an external apparatus. The IC card 10 of FIG. 1 may be used as a cash card, a personal identification card, or even a passport. For such a purpose, the key input section 13 may include, as shown, ten number keys 13a, a power key ON-C 13b which also serves as an all-clear key, a correction key COR 13c for making corrections on the information which has been entered, a match key 13d for checking the correctness of entered information such as a password and a read/display key R/D 13e for reading out stored information. In order to enter a password "2138" into such an IC card, for example, the user first presses the power key 13b and then the number keys "2", "1", "3", and "8" sequentially such that displays "0", "2", "21", "213", and "2138" appear sequentially in the display section 12. In order to check whether a correct password has been entered, the match key 13d is operated.
A prior art IC card of the type shown in FIG. 1 requires as many as 14 keys. In order to cram them within its surface of 85.5.times.54 mm in area, the individual keys are made extremely small and they are difficult to operate. If the portion of the surface area taken up by the key input section 13 is unreasonably increased, however, it becomes difficult to find an area for placing the display section 12. Since the card must remain thin, LSI circuit parts, etc. cannot be placed where the keys are provided and it becomes difficult to set various electronic parts of the IC card other than the input keys. Moreover, IC cards with a large number of input keys are expensive to manufacture.